Tuesday, December 21, 2010

And now for something kind of gross... The Common Tapeworm (Dipylidium caninum) is a parasite found in intestinal tracts around the world. It most commonly affects dogs and cats, though humans can also prey host to these creatures. Common Tapeworms require fleas in order to reproduce, and so must be in an environment that supports them as well. They can reach up to 20in (51cm) in length.

Tapeworm biology and reproduction is actually pretty fascinating. They attach to their host with a scolex, a hook like structure on their heads. Common Tapeworms are also hermaphroditic, and continuously grow new body segments during their lifetime. Each one of these segments contains an independent digestive and reproductive tract. New segments grow closer to the head, pushing the older ones farther and farther back until they drop off as an egg sac. These sacs eventually leave their host via feces.

And it just gets weirder. These eggs will hatch into larvae, but the larvae do not infect our pets or us. Instead, the larvae depends on the young of another parasitic species to spread. Young Fleas are voracious eaters, and consume the tiny Tapeworms. If a flea gets ingested (by a pet licking itself, for example), they pass the Tapeworms along, who them latch on and begin feeding and growing.

How does one get rid of a Common Tapeworm? Well luckily, we have pills and injections for these things now, but since they are spread by fleas, its also very important to rid your environment of those as well, in order to prevent re-infection. Humans affected by the Common Tapeworm often experience no symptoms, but abdominal pain and diarrhea can occur.